LTPP Traffic Data Pooled-Fund Study Underway

The Federal Highway Administration's (FHWA) Long-Term Pavement Performance (LTPP) program continues to move forward with its Specific Pavements Study (SPS) Traffic Data Collection pooled-fund study. The study is designed to fill in gaps and improve the quality and quantity of monitored traffic data from the LTPP program's SPS-1, -2, -5, -6, and -8 projects. To date, 20 States have contributed approximately $2.7 million to the study.

The SPS experiments were designed to learn how such factors as cumulative traffic loading affect pavements of different compositions, environmental conditions, and layer thicknesses. Answering these questions will help States design and build longer lasting, high-volume pavements.

The pooled-fund study will have two phases. Phase I will consist of assessing, evaluating, and calibrating the current weigh-in-motion (WIM) systems used to collect traffic data at the SPS sites across the country. During Phase II, new WIM equipment will be installed and maintained at test sites as necessary to ensure high-quality data collection. Data would then be collected from the sites until each site has 5 years of quality vehicle weight data. A contract for the Phase I work was awarded to MACTEC Engineering and Consulting, Inc., in August 2003, and site evaluations have begun. Results from the initial evaluations were presented at the Transportation Research Board annual meeting in Washington, DC, in January. FHWA expects to award the Phase II contract this spring.

State highway agencies and industry representatives still have the opportunity to join the pooled-fund study. To learn more, contact Deborah Walker at FHWA, 202-493-3068 (email: deborah.walker@fhwa.dot.gov) or visit the LTPP Web site at https://www.fhwa.dot.gov/pavement/ltpp/spstraffic/.

Find out about the LTPP program's accomplishments in 2003 and plans for the future by checking out the LTPP 2003 Year in Review report (Publication No. HRT-04-041), now available online at www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/2003yir.cfm.

The report looks at the LTPP program activities in such areas as data collection, analysis, products, field operations, and pooled-fund studies. Among other endeavors last year, the program published the report, Key Findings from LTPP Analysis 2000-2003, and launched DataPave online (www.datapave.com). Previously available only on CD-ROM, the new DataPave program contains the most current LTPP data for viewing and downloading. And while the SPS Traffic Data Collection pooled-fund study continued, work also began on the LTPP program's first data analysis pooled-fund study, "Effect of Multiple Freeze-Thaw Versus Deep Frost Penetration on Pavement Performance."

To learn more about the LTPP program's activities, contact Aramis Lopez at FHWA, 202-493-3145 (email: aramis.lopez@fhwa.dot.gov). A printed copy of the report can be obtained by contacting Mary Anne Deeney at FHWA, 202-493-3463 (email: mary.deeney@fhwa.dot.gov).